1. Field of the Invention
The present invention relates to a take-up device, and particularly to a take-up device for winding a sheet-shaped material such as sheet-shaped photosensitive material or image receiving material in the form of a roll.
2. Description of the Related Art
There has conventionally been known an image recording apparatus in which image recording processing is effected by using, as an image recording material, two kinds of sheet-shaped materials, i.e., a photosensitive material and an image receiving material.
In the image recording apparatus of this type, the photosensitive material and the image receiving material are accommodated in respective magazines, whose interiors are each set in a light-shielding state, in such a manner as to be wound in the form of a roll. Each time the image recording processing is effected, the photosensitive material and the image receiving material are each used in a state of being sequentially nipped and pulled out by pull-out rollers. Further, the image recording apparatus is provided with an exposure section in which an image is exposed onto a photosensitive material and a water applying section in which an image forming solvent is applied to the exposed photosensitive material. Moreover, a heat-development transfer section is disposed by the side of the water applying section. A plurality of guide plates and a plurality of conveying rollers are disposed each between the exposure section and the water applying section and between the water applying section and the heat-development transfer section so as to allow connection between the exposure section, the water applying section, and the heat-development transfer section.
The photosensitive material pulled out from the magazine and cut down to a predetermined length is processed in such a manner that an image is exposed onto the photosensitive material while the photosensitive material is nipped and conveyed by conveying rollers, and in the water applying section, water used as an image forming solvent is applied to the photosensitive material, and thereafter, the photosensitive material is fed into the heat-development transfer section. The image receiving material is pulled out from the magazine and cut down to a predetermined length in the same manner as in the photosensitive material, and is then fed into the heat-development transfer section by conveying rollers synchronously with the conveying of the photosensitive material. In the heat-development transfer section, the photosensitive material to which water is applied and the image receiving material are made overlapping each other. While both of the materials are conveyed in the overlapping state, the photosensitive material is subjected to heat-development processing and an image is transferred to the image receiving material, and therefore, a predetermined image is formed (recorded) on the image receiving material. Subsequently, the photosensitive material and the image receiving material are separated from each other and the image receiving material on which the image is recorded is pulled out from the apparatus.
On the other hand, in the conventional image recording apparatus such as the above, a used photosensitive material after having been separated from the image receiving material as described above is conveyed to a waste photosensitive material accumulating box provided within the apparatus, and the used materials are sequentially accumulated to be overlapping one another in the waste photosensitive material accumulating box in the direction in thickness thereof irrespective of respective sizes of used photosensitive materials.
For this reason, for example, when used photosensitive materials having different sizes are accumulated mixedly, a useless (unusable) space is formed within the waste photosensitive material accumulating box so that the capacity of the waste photosensitive material accumulating box, in which used materials can be accumulated, necessarily lessens. In other words, it is necessary to set the size of the conventional waste photosensitive material accumulating box like this correspondingly to a photosensitive material having the maximum size and the internal capacity of the waste photosensitive material accumulating box cannot be effectively utilized.
Further, there may be cases in which a curling is generated in the photosensitive material with water being applied thereto after the photosensitive material is heated and separated from the image receiving material. When the curling is generated in the photosensitive material, the photosensitive materials cannot be accumulated in the waste photosensitive material accumulating box in such a manner as to be sequentially and uniformly laid overlapping one another. Accordingly, in this case, it is necessary to take measures to provide a presser plate for preventing occurrence of the curling, increase rigidity of the photosensitive material by providing folds (corrugation) in the photosensitive material itself, or the like. For this reason, the structure of the apparatus becomes complicated and the cost thereof increases.
In addition, in the above-described conventional image recording apparatus, the used photosensitive materials are sequentially accumulated overlapping one another in the direction in thickness thereof. Accordingly, in order to detect the limit of accumulation and calculate the ratio of an existing accumulation amount with respect to the maximum allowable accumulation amount (i.e., an accumulation ratio), for example, by detecting an angle .theta. formed by a pressing member 334 for pressing down used photosensitive materials 332 accumulated as shown in FIG. 14 and the side surface of an image recording apparatus 330 and on the basis of the angle .theta., the thickness of the used photosensitive materials 332, i.e., the existing accumulation amount is detected.
However, the above-described accumulation-amount detecting method cannot be applied to a case in which a sheet-shaped material is wound around an outer periphery of a predetermined core member.
In view of the above-described circumstances, it is an object of the present invention to provide a take-up device of image-forming sheet-shaped materials such as a photosensitive material and an image receiving material, in which the image-forming sheet-shaped materials can be effectively accumulated in a small space.
Another object of the present invention is to provide a take-up device which allows calculation of a winding ratio of an existing winding amount with respect to the maximum winding amount of a sheet-shaped material in the structure in which the sheet-shaped material is wound around an outer periphery of a predetermined take-up core member.